Shuttle race for sewing machines



Allg- 2, 1932- E. B. ALLEN 1,869,402

SHUTTLEvRACE FOR SEWING MACHINES Filed July 16, 1931 2 Sheets-Sheet l Aug. 2v 1932.

E. B. ALLEN SHUTTLE RACE FOR SEWING MACHINES Filed July 16. 1951 2 Sheets-Sheet 2 7 IN1/EN TOR ATTORNEY Patented Aug. 2, 1932 UNITED STATES PATENT oFFIcE EDWARD B. ALLEN, F NEWTOWN, CONNECTICUT, ASSIGNOR T0 THE SINGERIWANU- l FACTURNG COMPANY, 0F ELIZABETH, NEW JERSEY, A CORPORATION OF NEW JERSEY SHUTTLE RACE FOR SEWING MACHINES Application filed July 16, 1931. Serial No. 551,115.

This invention relates to sewing machines, more particularly of the two-thread lockstitch type having a reciprocating needle and a loop-taker carrying a bobbin of' under thread. In machines of this type it is customary to journal the loop-taker in a supporting raceway, and this raceway must be very accurately machined if the machine is to run quietly and perform satisfactorily. Attempts to harden a machined loop-taker raceway to reduce wear, have been unsuccessful because of warping of the raceway under the heattreatment necessary for hardening. If the raceway is hardened before it is machined to finished size, expensive and dithcult corner grinding operations are required where the side bearing surface of the raceway meets the internal cylindrical bearing surface. The wear on an unhardened raceway, in addition to making the machine noisy, causes particles of worn olf metal to be mixed with the raceway lubricant, thereby producing black oily smudges on the sewing threads and damaging the work.

The present invention has for an object to provide a sewing machine loop-taker and raceway construction which is clean running and which can be expeditiously and inexpensively manufactured with a high degree of precision.

To the attainment of the ends in View the invention comprises the devices, combinations andarrangements of parts hereinafter described and more particularly pointed out in the claims.

The features of the invention and the advantages attained thereby will be readily understood by those skilled in the art from the following detailed description of a preferred embodiment of the invention illustrated in the accompanying drawings in which Fig. 1

is a front face view of an improved raceway Y for a loop-taker of the oscillatory shuttle type. Fig. 2 is a perspective view of the sewing machine bed-casting which carries the raceway. Fig. 3 is a section through the raceway removed from the bed-casting of Fig. 2 and taken on the line 3-3, Fig. 1, the shuttle being shown in top-plan. Fig. 4 is a disassembled perspective view of the raceway.

Fig. 5 is a vertical section on the line 5 5 of Figs. l and 3, and Fig. 6 is aperspective view of the inner face of the raceway removed fromthe machine. Y v

The sewing machine vbed-casting 1 is formed with a central supporting leg 2 the sides of which are widened at 3, .3 and faced to form a seat 4 to which is secured by screws 5, 5 a raceway support 6 in the form of a ring-shaped casting of ordinary unhardened metal such as cast-iron. The raceway support 6 is formed with a circular centralizing rib 7 which enters the concentric segmental grooves 8 in the faces 4 of the widened portions of the leg 1.

The detachable raceway suppo-rt 6 has its inner face bored out to form a cylindrical seat 9 and end face 10 square with the seat 9, the two constituting a circular pocket for the liner assembly to be described.

The liner assembly comprises a plurality of stacked rings of hardened steel. There is an inner face ring 11, an intermediate bearing ring 12 and an outer face ring 13. y

These rings have their opposite faces finished by simple flat grinding operations and the outer cylindrical surfaces of the rings 11 and 12 are cylinder ground to fit the turned cylindrical seat 9 in the support 6. The vinner cylindrical surfaoerof the intermediate ring 12 is cylinder ground to form a supporting bearing for` the circular bearing rib 14 of the usual oscillatory shuttle 15 having the loop-seizing beak 16 and the throat 17 and heel 18 which are engaged by the arms 19, 20 of the usual oscillatory shuttle driverv 21 carried by the shuttle driving shaft 22 journaled at one end in the leg 2. The inner cylindrical surfaces of the rings 11 and 13 may also be finished by plain cylinder grinding operations although these surfaces do not of the intermediate ring 12 is greater than the inside diameter of theV rings 11 and 13. Hence when these rings are stacked together there is formed a bearing groove for the rib 14 of the shuttle.

To assist in assembling the rings and to prevent circular displacement thereof relai" rra er b.

tive to one another and to the racevvay support 6, doWel pins 23 are provided. These pins pass through the several rings and into doWel-pin apertures 24 in thel support 6. rIhe ends of the doWel pins-23 project outwardly beyond the ring 13 and serve to locate and prevent displacement of the ends 25 of the Ushaped leaf-spring 26 which is secured by the screvv 27 to the racevvay support 6. The spring 26 permits the ring 13 yto yield relative to the rings 11`and 12 and permits of the maintenance of a snug bearing Without danger of sticking. The usual bridge-piece 28 is secured to the ring 12 and has end fingers 29 overlapping the 'upper faces 30 of the support 6.

VIt will be observed that by virtue of the present improvement a hardened loop-taker raceWay may be provided. at minimum eX- pense. All of the finished bearing surfaces maybe ground to size with a high degree of precision and by simple and inexpensive fiat andcylinder grinding operations. rI`he supporting castings 6 may be cheaply turned in quantities in armonitor lathe. The rings 11, 12and 13, after being fiat ground to parallel planes may be stacked (like rings in each stack) and cylinder-ground in quantities.

Having thus set forth the nature of the invention, What I claimfherein is 11.; In a sewing machine, a loop-taker race- Way comprising a'support having a machine turned; cylindrical seat and av plurality of hardened ring-shaped liners received in said seat, said liners having their opposite faces flat-ground to parallelism and one of them having its inner surface cylinder-ground.

2v. In a: sevving machine, the combination With a loop-takerhaving a circular bearing rib, of a racevvay for said rib including a support having a machine-turned circular pocket and a linerv assembly removably received in said pocket, said liner assembly including a plurality of hardenedrings having their side faces fiat-ground to parallelism, one of said rings also having its inner surface cylinder-ground to lit the cylindrical surface of said bearing rib.

3. In a sewing machine, the combination With a loop-taker having a circular bearing rib, of a racevvay for said rib-includin 'a support having amachine-turned circu ar pocket and a liner assembly removably received in said pocket, said liner. assembly including a plurality of hardened rings hav- Y ing their side faces fiat-ground, one of said rings also having its inner surfacecylinder- Y ground to ht the'cylindrical surface of said in said pocket, said liner assembly ineluding a plurality of hardened rings having their side faces flat-ground, one ofsaid rings also having its inner surface cylinder-ground to fit the cylindrical surface of said bearing rib, and a plurality of dovvel pins for posi#` tioning said liners relative to one another and to said seat.

5. kIn a sewing machine, a `loop-taker racevvay comprising a support having a machinee turned cylindrical seat, and'three ring-shaped members disposed in stacked relation Vand secured to' said seat, said members being made of hardened steel and having their opposite faces fiat-ground to parallelism, the intermediate member having its-inner surface-CyL inderground to a diameterl greater than the inside diameterof theadjacent ringshaped members. y

6. In a sewing machine, a looptaker race- Way comprising-a support having a machineturned cylindrical seat, and three ring-shaped members disposed in stacked relation and secured to said seat, said members being made of hardened steel and having theiriopposite faces flat-ground, the intermediate member having its inner surface cylinder-ground to a diameter greater thanthe inside diameter of the adjacent ring-shaped members and a` leafespring for holding said members in operativeposition relative to said seat.

In testimony whereof I have signed my name to this specification.

EDWARDy B. ALLEN.

bearing rib, and dovvel-pins for positioningv said liners relative to one another.

4l. In a sewing machine, the combination With a loep-taker having 5a circular bearing rib, of a racevvay for said rib including a support having a machine-turned circular pocketv and a liner assembly removably received 

